CIBJO and “Synthetic,” a Rare Watch and Gem: ‘The Jewelry District’ Podcast

By Natalie Chomet | December 03, 2025

In the latest episode of The Jewelry District, JCK news director Rob Bates talks about the hot topics at last month’s World Jewellery Confederation (CIBJO) Congress in Paris, including the question of whether CIBJO should change the terminology around lab-grown diamonds in its Blue Books. JCK editor-in-chief Victoria Gomelsky covers Phillips’ record-breaking Decade One watch auction and its star lot, a 1943 Patek Phillippe with an intriguing story. Finally, the hosts discuss another rare item with a mysterious history: the Florentine Diamond.

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Title sponsor: Nivoda (nivoda.com)
Sponsor: De Beers (adiamondisforever.com)

Show Notes
01:20 Takeaways from the CIBJO Congress
10:50 The story behind the star watch in Phillips’ Decade One auction
18:10 Gold price and the high-end jewelry market
19:40 The Florentine Diamond reappears

Episode Credits
Hosts: Rob Bates and Victoria Gomelsky
Producer and engineer: Natalie Chomet
Editor: Riley McCaskill
Plugs: @jckmagazine; nivoda.com; adiamondisforever.com

Show Recap
Takeaways from the CIBJO Congress
Rob shares his experience attending the CIBJO Congress in Paris. He anticipated that discussion at the conference would center on the controversial issue of whether CIBJO should mandate calling lab-grown diamonds synthetic in its Blue Books. However, there wasn’t as much debate as Rob expected. “It seemed like a lot of people had already made up their minds [in favor of the new terminology],” he says, noting that if the organization decides to make the change, it would have to go through several committees before it came to pass.

Rob’s take on the issue? Though the label lab-grown may not be glamorous, it works—and makes sense to consumers. Insisting on using synthetic seems like a punitive response to the growth of the lab-grown diamond market. “The only reason they would go for synthetic is because it sounds worse,” he says. The term lab-grown is already established in the United States, so Rob says he’s not sure what CIBJO can do.

“The way someone put it to me, they felt very used by the lab-grown companies—they came in and totally disrupted the industry, and a lot of them are pivoting to tech,” Rob explains. “I could have told them a couple of years ago that would happen.”

He says the natural diamond industry had been dealing with flagging demand even before lab-grown diamonds came on the market. “This is a long-term problem the industry has to face,” Rob says. “Going negative might work in the short-term, but it doesn’t necessarily boost demand for the overall category. You are just grabbing share from the overall pie.”

Just like natural diamond companies, lab-grown diamond suppliers face challenges, he adds. “Long-term, I don’t think much is gained by going negative,” Rob says. “I think it’s better to work together.”

Other big topics at the CIBJO Congress included tariffs and the role of AI in the jewelry industry’s future. The consensus was the tariff situation remains in flux, as the conference took place right after the U.S. Supreme Court hearing where some justices expressed skepticism about the president’s ability to impose tariffs.

The discussions at CIBJO make one thing clear: No one knows what’s going to happen. “These industry forums are always good for networking and for hearing what people have to say. But I think what it really comes down to is there are no easy fixes or easy answers,” Rob states.

The story behind the star watch in Phillips’ Decade One auction
Victoria fills us in on a Geneva watch auction that marked multiple milestones. Phillips celebrated 10 years in the watch space with its Decade One auction, and the sale proved to be record-breaking. Its headline lot, a 1943 Patek Philippe ref. 1518, sold for about $17.6 million, and the auction overall was the highest-grossing watch auction to date, with a staggering total of $83 million in sales.

A heady combination of factors made the Patek Philippe watch so special: rarity, provenance, and a fascinating history. The 1518 model is significant because it was the first perpetual calendar chronograph serially produced by any brand—not just Patek Philippe. “Every model that Patek has made since then has used the same essential layout as this reference 1518,” Victoria says. The 1518 had a limited run of production in the 1940s, with only 281 watches created. Out of those 281, four were made in steel—and this is one of those four.

On top of the rarity and historical significance of the model, it has another characteristic that collectors value: a good backstory. This particular watch was one of the two steel models shipped to a Hungarian retailer in 1943, while Europe was in the thick of World War II. “It sets your mind going, What were they ordering fancy watches for?” Victoria wonders.

The watch made its way through the market, resurfacing in the 1980s, when wristwatches were just starting to become the collectibles they are today. “For most of the 20th century, it was clocks, pocket watches, and only in the ’80s did the wristwatch collecting category really come into its own,” says Victoria.

The historic Patek sat in the window of a store on 47th Street in New York City for years before it was sold again. It was purchased at a Phillips auction about 10 years ago for $11 million, and that owner sold it at Phillips’ Decade One auction. “It shows, certainly, the strength of the market for very rare, special pieces,” Victoria says. And this auction’s record-setting sales total during a period of economic uncertainty says something about the strength of the secondary watch market, she adds.

Gold price and the high-end jewelry market
Rob notes there has been talk of a slight slowdown in the secondhand watch market at the midlevel—and that brings the hosts to a larger point: Across many categories, but especially in high-end jewelry and watches, business is booming.

There are a few reasons the soaring gold price hasn’t slowed the luxury jewelry market down. One is that high-end jewelry is often stone-intensive. “The gold is there to support the stones. It’s not about the gold,” Victoria says. So the cost of the gold can be absorbed more easily when there are lots of diamonds and other precious stones in the pieces.

The appetite for luxury jewelry hasn’t abated, and price doesn’t appear to be a barrier. Victoria shares an example of this: At a David Webb preview, she saw a chunky zebra bangle—made of black enamel, white diamonds, gold, and platinum—priced at $275,000, and it was already sold out. “It wasn’t one-of-a-kind. They’d put in workshop orders, and it had flown,” she says. “I do think that jewelry is incredibly resilient.”

The Florentine Diamond reappears
To wrap up the episode, Rob turns to another jewelry piece with a fascinating history: the Florentine Diamond. For over a century, people believed that the famous 137 ct. yellow pear-shape diamond had been lost. Now the truth is out.

The Florentine’s last known owner was Charles I of the Hapsburg family, who ruled Austria until 1918. When the family fled Austria at the end of World War I, no one knew what happened to the diamond. Stories and theories flew for decades: Some said it was stolen, others believed it had been recut. A few decades ago, a diamond turned up that people believed was the Florentine (it wasn’t), which only served to revive the mystery.

The truth turned out to be the simplest explanation: When the Hapsburgs fled to Switzerland and eventually Canada, they took the Florentine Diamond with them. But the family never revealed this fact. “Apparently at one point it was being carried around in what they called a ‘small cardboard suitcase,’” Rob says.

Empress Zita, widow of Charles I, stashed the diamond in a bank vault in Quebec and told only her two sons about it. She asked them keep the gem’s whereabouts secret for 100 years after Charles I’s death (in 1922). Then this fall, the family decided to invite a New York Times reporter to the bank vault to see it.

The family doesn’t know how much it’s worth and says they don’t plan to sell it. They would instead like to display it in Canada, because it was the country that sheltered them during World War II.

“You can see why there’s so much allure to the stories of these big stones and historic pieces,” Victoria concludes.

Any views expressed in this podcast do not reflect the opinion of JCK, its management, or its advertisers.